Amgen reports promising Phase 2 results for skin-focused lupus antibody

Amgen reported fuller Phase 2 results for daxdilimab, an antibody it acquired with Horizon Therapeutics, in 72 people with moderate-to-severe discoid lupus, a form of lupus that primarily affects the skin.

At Week 24, the lower dose produced a 6-point placebo-adjusted improvement on the CLASI-A skin disease activity scale; the higher dose produced a 5.7-point improvement. Amgen said both doses met the trial’s primary endpoint.

About 62% of patients in each dose group achieved at least a 50% reduction in CLASI-A, compared with 23.7% on placebo. On a clinician-rated scale, 60.3% on the lower dose and 51.6% on the higher dose reached a score of 0 or 1, versus 8.9% on placebo.

The result is an early clinical win, not proof of approval or effectiveness across all lupus. Daxdilimab previously failed to beat placebo in a Phase 2 trial for systemic lupus, the more common form; Amgen has said it is taking steps toward registrational development in discoid lupus.